Device and a method for molding an elastomer bearing onto a stabilizer bar

Abstract

The present invention provides a method of molding an elastomer bearing onto a stabilizer bar in which the following steps are performed: placing a stabilizer bar across a mold; injecting an elastomer into an empty space formed between a first portion of the bar and the mold; hot-curing said elastomer, firstly by induction heating the mold using first induction heating means, and secondly by induction heating said first bar portion by second induction heating means disposed around two second bar portions situated on either side of the mold; and unmolding the bearing that is obtained once the elastomer has cured. The invention also provides apparatus enabling the method of the invention to be implemented.

1 . A method of molding an elastomer bearing onto a stabilizer bar, the method comprising the following steps: placing a stabilizer bar across a mold suitable for leaving a closed empty space having the shape of said bearing around a first portion of said bar; injecting a composition comprising at least one elastomer into said empty space; hot-curing said composition by induction heating the mold and by heating said first portion of the bar by using induction heating means disposed around at least one second portion of said bar that is situated outside the mold; and unmolding the resulting bearing after the composition has been cured.  
   
   
       2 . A method according to  claim 1 , wherein said first portion of the stabilizer bar is heated, at least in part, by heat conduction from the second portion towards the first portion of the bar.  
   
   
       3 . A method according to  claim 1 , wherein said mold and said second portion of the stabilizer bar are heated by induction prior to injecting said composition.  
   
   
       4 . A method according to  claim 1 , wherein a bonding agent is deposited on said first portion of the stabilizer bar prior to injecting said composition.  
   
   
       5 . A method according to  claim 1 , wherein different induction heating means are used for heating said mold and for heating said second portion of the stabilizer bar.  
   
   
       6 . A method according to  claim 5 , wherein said induction heating means are controlled independently.  
   
   
       7 . A method according to  claim 5 , wherein said induction heating means are controlled in such a manner that the temperatures of the mold and of the first portion of the bar lie in the range 160° C. to 220° C.  
   
   
       8 . A device for molding an elastomer bearing on a stabilizer bar, the apparatus comprising a mold suitable for leaving a closed empty space having the shape of said bearing around a first portion of stabilizer bar, an injector for injecting a composition comprising at least one elastomer into said empty space, first induction heating means for heating said mold, and second induction heating means for heating at least one second portion of the bar situated outside the mold and in the vicinity thereof.  
   
   
       9 . A device according to  claim 8 , wherein said second induction heating means are disposed on either side of said mold.  
   
   
       10 . A device according to  claim 8 , further comprising control means for controlling said first and second induction heating means independently of each other.  
   
   
       11 . A device according to  claim 8 , wherein said mold is made up of two half-shells, and wherein said first induction heating means comprise two half-inductors each formed by a conductor element of undulating configuration enveloping the outside wall of a respective one of the half-shells.  
   
   
       12 . A device according to  claim 11 , further comprising non-conductive supports associated with said half-shells, the support presenting on their sides spacers suitable for maintaining each support at a distance from the associated half-shell, and wherein each above-mentioned half-inductor is housed between one of the two supports and the associated half-shell.  
   
   
       13 . A device according to  claim 12 , wherein each support is secured to a plate of an injection press.  
   
   
       14 . A device according to  claim 11 , wherein said injector passes through one of the half-shells, with an abutment forming a reaction against injection being situated on the other half-shell, facing said injector.  
   
   
       15 . A device according to  claim 8 , wherein said second induction heating means comprise at least one conductor element of undulating configuration, said conductor element surrounding at least part of the second portion of stabilizer bar.  
   
   
       16 . A device according to  claim 11 , wherein the conductor element of the first and/or second heating means is/are constituted by a metal tube having a liquid flowing therein that is suitable for cooling said tube.  
   
   
       17 . A device according to  claim 15 , further comprising at least one resin base having the conductor element of the second heating means embedded therein.  
   
   
       18 . A device according to  claim 17 , wherein each support is secured to a plate of an injection press, and wherein said resin base is secured to one of the two plates of the injection press.